Space killifish offer hope on treatment for osteoporosis

Astronaut Koichi Wakata, the commander of the International Space Station, has found bone-resorption cells of “medaka” killifish active in scientific research being carried out in space, the Japan Aerospace Exploration Agency said Feb. 17.

The experiment is designed to discover how microgravity affects bones, using genetically modified young medaka so their bone-formation and bone-resorption cells can glow. Wakata studied cells raised in space with a microscope.

“If we find out the mechanism of bone metabolism, it can possibly lead to development of a treatment for osteoporosis,” a JAXA official said.

Footage sent from space showed cells that work to break down bone tissue and those that work to form cells have become active in the space killifish, JAXA said.

It is known that the mineral density of bones in humans greatly decreases during a long stay in space. The latest observations found bones supporting the teeth in the fish’s throat glowing yellow, showing that both kinds of cells have been activated.

Bones in the throat of a killifish kept in the experiment module Kibo at the International Space Station are shown. Yellow portions show bone-formation and bone-resorption cells actively at work. (Provided by co-researcher Akira Kudo, professor at the Tokyo Institute of Technology)